Abstract P467: Left Atrial Appendage Occlusion and Risk of Stroke in Medicare Beneficiaries

Background: Atrial fibrillation (AF) is a significant risk factor for stroke, with oral anticoagulants (OACs) recommended for stroke prevention. However, a nonpharmacologic option is needed for patients with contraindications for OACs. Recently, percutaneous left atrial appendage occlusion (LAAO) has emerged as an alternative treatment option. Although clinical trials have shown that percutaneous LAAO is non-inferior to warfarin and direct OACs, few studies using real-world data have been done. Methods: Using data from the Medicare 20% sample databases (2015-18), we assessed the association between percutaneous LAAO vs. OAC use and risk of all stroke among patients with AF who had an elevated CHA 2 DS 2 -VASc score. Secondary outcomes included death and hospitalized bleeding. Patients undergoing percutaneous LAAO were matched with up to 5 other patients who were taking OACs by sex, age, date of enrollment, index date, and CHA 2 DS 2 -VASc score. A total of 17,514 patients with AF were matched (average [SD] 78 [6] years, 44% female). Cox proportional hazards model was used. Results: Over a median follow-up of 10.3 months, 293 stroke events, 1,925 deaths and 618 major bleeding events occurred. After multivariable adjustments, no significant difference for risk of stroke or death was noted when patients with percutaneous LAAO was compared to those taking OACs (HRs [95% CIs]: 1.25 [0.95, 1.67] and 0.94 [0.83, 1.06], respectively). However, there was a 3.24-fold (95% CI: 2.75, 3.81) increased risk for hospitalized bleeding after percutaneous LAAO compared to OAC. Conclusion: Using data from the Medicare 20% sample databases, no significant difference in risk of stroke or death were noted when percutaneous LAAO was compared to OAC users. However, there was an increased risk for bleeding. Our results confirm the results of randomized trials that among older patients with AF and a high-risk for stroke, percutaneous LAAO may be an alternative to OAC use; however, patients should be aware of potential risks associated with the implantation.